Haven't NZ been using CX in its Aussie ports for a couple of years now, since they dictheched QF.
NZ only used CX in SYD for a few years until they set up their own station there 2 years ago. Line maintenance providers as of now (for NZ):
SYD/BNE/MCY - self handled
MEL/PER - JHAS
ADL/CNS - Qantas
OOL - AMSA
Rumours about PER and MEL being self handled have been doing the rounds apparently.